A transparent display refers to a display that allows light to transmit through to a certain extent. Hence, the background on the rear side of a transparent display is clearly viewable when a user is viewing the display. Owing to the property, transparent displays are applicable in our daily lives to facilitate information propagation. For example, transparent displays are applicable in smart windows, advertisement bulletins, vehicle mount displays, and the like.
In order to pursue high transparency, a transparent oxide electrode is disposed in a transparent light-emitting apparatus in the transparent display to facilitate the transparency. However, since the transparent oxide electrode has a higher refractive index, waveguide may be formed easily in the transparent light-emitting apparatus, resulting in a great amount of energy limited in a waveguide mode and thus making the energy unable to be utilized effectively. Hence, the brightness of the transparent light-emitting apparatus is highly reduced.